#include <iostream>
#include <glad/glad.h>
#include <GLFW/glfw3.h>

void frame_buff_size_callback(GLFWwindow* window, int width, int height);
void process_input(GLFWwindow* window);

int main()
{
    // GLFW INIT
    glfwInit();
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

    GLFWwindow* window = glfwCreateWindow(800, 600, "Hello World", nullptr, nullptr);
    if(window == nullptr) {
        std::cout << "Failed to create GLFW window" << std::endl;
        glfwTerminate();
        return -1;
    }
    glfwSetFramebufferSizeCallback(window, frame_buff_size_callback);
    glfwMakeContextCurrent(window);

    // GLAD
    if(!gladLoadGLLoader(reinterpret_cast<GLADloadproc>(glfwGetProcAddress))) {
        std::cout << "Failed to initialize GLAD" << std::endl;
        return -1;
    }

    glViewport(0, 0, 800, 600);

    while (!glfwWindowShouldClose(window)) {
        process_input(window);

        glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT);

        glfwSwapBuffers(window);
        glfwPollEvents();
    }
    glfwTerminate();
    return 0;
}

void frame_buff_size_callback(GLFWwindow* window, const int width, const int height) {
    glViewport(0, 0, width, height);
}

void process_input(GLFWwindow *window) {
    if(glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
        glfwSetWindowShouldClose(window, true);
}
